Monthly Archives: March 2012

Fishers of the North Country

Well since I talked about female fishers yesterday I though it was only fair to give the males a little play today. Fortunately, one male in particular has given us some new and interesting things to talk about. First, a little background is in order.

As some of you might know in the first year of the translocation we had a male that almost immediately after release bolted north about 50 km near the town of Manton. He stayed in that area until his transmitter failed in June of 2010. Some recent photos from that area, just north of Shingletown, CA, indicate that this male is still in the area – though we have yet to recapture this animal to confirm. We grew to call this the “Manton male” for reasons that are hopefully apparent.

In year 2, the first male we released roamed quite a bit. As a matter of fact his satellite transmitter indicated that he was all the way into the central valley (not what we think of as typical fisher habitat) on at least one occasion in January of 2011. Unfortunately, we lost track of this fellow sometime in mid 2011 and we did not know where he had gone until the fall when we captured him near Manton (while we were trying to recapture the original Manton male). In the time since his capture he had not wandered that far from the capture area, and so it appear that this is now a big portion, if not the core, of his home range. So, in two years we had two males that found there way to roughly the same area. By the way, we have no indication that other fishers live in the area.

Okay, so now we are in year 3 of the translocation. Several new males have been released and they all stayed roughly in the areas where we released them. Well, until about 2 weeks ago anyway. On March 12 male 24315 suddenly moved about 15 km north. He then moved further north, you guessed it, to right around the Manton area. In the last several days he has moved another 15 km north of Manton! So, now we have three “Manton males”. I’ve included a couple of maps showing locations for all three of the males I’ve described. The first map is a larger scaled view and shows a good cross section of where we have located all three males. The second map is a closer view of just the northern locations and roughly centered on the Manton area. The second map also shows an approximate time line for male 24315 during the last 2 weeks.

The movements of these males are curious to me because they all went north and stopped or slowed down in the same area. We have had no males travel, and stay, south or east of their release locations though we might predict that we would observe this if males were striking off in random directions. So, why are are we seeing this apparent pattern of males traveling north? The short answer is “I don’t know”. Unfortunately, we still just don’t know enough about what sort of directional or environmental cues males might be using to guide them. Moreover, what resources or restrictions cause them to end up in the same general area is also unknown. The most logical answer is that there are female fishers in the area, but camera surveys in the area – conducted over the last two years – simply do not detect other non-collared fishers. It is possible that male 24315 will come back south. This is after all the breeding season and males have been known to travel a long way to find females. For now, I suppose why these males have traveled north will remain a mystery. So, “if you’re traveling in the north country fare” keep your eyes open and maybe you’ll be lucky enough to spot one of these males in their many travels.

Locations of three male fishers

Time series of male 24315's movements from March 12- March 28, 2012

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DENizens of the Trees

In the last 2 weeks we have managed to confirm that at least 5 of our females have settled into patterns consistent with denning behavior. We detected the first on about March 21 and that is the earliest we have detected a female in a den over the last 3 seasons (more on that  later). Three of the females were released in year 2 of the translocation. One of those females did not den last year and 2 did. The other females were those released in year 3. This is positive because it shows that the females from last year found mates and appear to have had kits. We demonstrated this last year with first year animals, but observing it for the second year adds data and understanding to important population processes. Matt observed a male fisher at female 1F111’s den tree already this year. This was a female released in year 3  and the den is about 11 km east of where we released her. I am still amazed that males show up at den trees seemingly right after females establish them, but since that is a male fishers specialty I guess I shouldn’t be surprised at all.

Black oak den tree

The dens are spread across a big swath of the district. From the west side in the Big Chico Creek Drainage to the east side near highway 70. We even have one female denning on the north side of Deer Creek. We still have a lot of females that have yet to den so it should be interesting to see the distribution of their dens when all is said and done.

Den tree (on right) of female 1F111

The first two years of the project  the earliest we ever found a den was March 23 and most were found after April 1. This year we have found 3 dens before March 23 and another 2 before the 26th, One reason for this might be that we have better access to where females are because we have had relatively little snow accumulate over the winter. The last two years we were snowmobiling/snowshoeing into dens through much of April. Alternatively, the relatively mild winter might have simply allowed females to den a little bit earlier (some anyway) because they were in a better condition. At least three of these females appear to have never given birth before (based on past tracking and physical examination), and this could influence their body condition and timing of birth. All of this is speculation of course, and the bulk of females have yet to den so we might just be observing natural variation in timing of births. It will be interesting to see if other studies detect earlier than usual denning behavior.

We’ll be putting cameras on all the den trees we find to document when females move their litters to maternal dens and to make minimum estimates of their litters sizes. More information to come….

A view of the area immediately adjacent to a fisher den

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Fowl Weather

Yesterday was one of those days where it lightly rains all day.  The kind of day which shows you that every piece of “waterproof” gear you own is really only “water-resistant”, and one of the rare times that you wish you were doing office work.  These are also the kind of days which riding on a 4-wheeler for eight hours isn’t very fun.

Angry bird.

While I was out roaming around searching for fishers, I whizzed by something moving on the side of the road.  As with anything a little unusual, I stopped to take a look.  I glanced back to see a male grouse walking towards me.  He continued until he was about a foot from the ATV, and then proceeded to circle me.  Obviously I was on his turf.

After a half-dozen laps, he decided to jump up on the ATV with me.  Now a grouse isn’t a bird which one would think of as particularly fearsome, but I must say I jumped off pretty quickly when he climbed up.  He strutted around on top on the ATV for a couple of minutes, king of his new territory.

Looking to go for a drive.

However, shortly after I had been separated from the relative safety of the ATV, he decided it was time to jump down, chase after me, and attack my legs.  Fortunately for me, out maneuvering a grouse isn’t particularly difficult.  I ran around to the other side of the ATV, jumped back on, and got the heck out of there.

I don’t see many grouse around here.  They occasionally have surprised me by exploding from underneath my feet as I was walking through the forest.  It was cool to get a close look at one, however this was much closer than I needed to be!  I took a video of him circling around me, which you can watch HERE.

These are the kinds of things that happen which make a dreary day a little more enjoyable.



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Fisher Talk

No particularly exiting news presents itself today, but I thought I would provide some content to distract folks from doing actual work (maybe).

Last year Roger gave a talk about weasels and fishers to a group in Ely, MN (where he currently resides). I’m not sure why I was searching, or found them  but I came across those talks and they are enjoyable so check them out here. There are several videos but once you get to the first link you should be able to find them all. Roger gives some nice general information on fishers and weasels along with some nice slides – he throws in a joke now and then too.

I’m off to track fishers. Enjoy



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Judging by the Cover

For those of you interested in such things a new book has recently been published on Carnivore Ecology and Conservation by Luigi Boitania and Roger A. Powell (yes our very own Roger). It is full of all kinds of useful information about capturing, handling, tracking, and generally studying those lovable meat eaters that we all enjoy learning about so much. Contributions to the book being made by not only Roger but also by other folks from our project (check out chapters 9 and 13 first) as well as a number of very accomplished researchers.

I have yet to read every chapter, but have already read the chapter on home ranges and movements. A lot of very good information in there, and I assure you I’ll be reading it again. I’ll spare you all from a full blown book review any time in the future as that would probably be painful for all involved.  Yes, some might say I have a conflict of interest here since Roger is my adviser, but hey I”m not one to pull punches when I need to (can anyone tell me how many times the  word “tecs” needs to be on a cover?).

Anyway, if you have some spare cash (and I don’t) it is a worthwhile piece to add to your library.


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Red-tailed Peril

To add to my previous post I thought I’d share one of the more impressive series of images from a den thus far;

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We believe the Red-tailed Hawk you can see entering and exiting the upper left of frame in this series was attempting to steal the prey item being carried by female 199B9 (center frame) to her natal den in April 2011. Whatever the reason, she survived unscathed and went on to occupy 2 maternal dens through the 2011 season before her VHF transmitter finally failed.


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The Great Kit Debate

In a somewhat desperate bid to up my posting rate I’m going to revisit old ground in this post and return to a brief email debate from last April.

And so a brief background is in order…

As we build up to this years denning season we have begun the task of collating and analyzing our camera data from the first two denning seasons on Stirling. As many of you may know the season really begins to heat up in early April as we confirm natal dens (a natal den is the den in which a female gives birth to her kits) by performing walk-ins on stationary females. It is usually on the second walk-in to a given tree that we consider the female has indeed denned. At this point we set a series of remote cameras around the den structure in order to passively monitor the females activities. Through the denning season a female Fisher will usually progress from her natal den through a number of maternal dens (a maternal den being any den occupied after the natal den). Thus one of the most exciting things we see on our cameras is the female carrying her kits out of the den, this gives us a great opportunity to count the number of kits.

So here the debate arises. While going through our pictures of female 17582’s natal den from the 2011 season I came across some familiar images, the first image is of 17582 moving her first kit from the natal den to her first maternal den roughly 100 yards away. Nothing too contentious there.

The picture below was taken 20 minutes later and appears to show her moving a second kit, or potentially a second and third kit at the same time, as the wily Roger Powell contended.

And here is the same image expanded;

So I ask your opinion,


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